You would most likely have to build it yourself. You can probably find schematics for a surface mount AM transmitter. That particular one was actually built by Oak Ridge National Laboratories and has a range of 3 kilometers. If you wanted them to produce another for you it would probably cost an arm and a leg more than what Miniboy is worth in hours and material price.

As an interesting side note, when fired at 55 degree elevation, the A2 will travel 113,111 meters (123,630 yards or roughly 70 miles) and reach a height of 44,073 meters (48,171 yards or almost 27 miles). You are NOT safe if someone aims one of these at you. The accuracy of the dart is sub-MOA and the stated effective range is about 3000 meters (3270 yards). However, first round killing hits have been obtained out to about 6000 meters (6540 yards).

Sharp-eyed readers may note the 55 degree elevation for the maximum range of this projectile. While spin stabilized cylindrical projectiles reach their maximum range in air at angles of between 25 and 35 degrees (45 degrees in a vacuum) the "dart is fin stabilized and not spun (the 120 mm gun is a smooth bore) and this gives it its maximum range at 55 degrees elevation--the fins keeping it point first through out its trajectory and providing some lift. Click here for a discussion of projectiles fired at extreme elevations.

Note also the discrepancy between optimum launch angles between spin and fin stabilised projectiles.

DYI wrote:Jack's reference measured from the horizontal. An M892A2 round has a high enough muzzle speed and low enough drag that it goes high enough for the reduced air density to make a difference. A similarly extreme example of the effect can be seen in the Paris Gun of WW1.

Your friend's dad is not an engineer if he's incapable of such basic dimensional analysis, or the intuitive understanding of low-altitude trajectories. I suggest euthanasia.

AAh, I failed to consider reduced air density.

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POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name

I've had a long day at uni today and during most long days at uni my mind frequently drifts back to the MiniBoy and the problem of locating him.

Have we discussed a FM transmitter (assuming I can make one cheap enough and small enough) that fits inside MiniBoy with an antenna coiled up inside that is attached to the tail and on impact, the tail comes loose and stays on the surface while the projectile is buried?

There are a number of problems with this that I immediately recognise:
1: buying/making the transmitter
2: the survival of the components (some epoxy should fix this)
3: the tail detaching prematurely, not at all or being dragged down slightly before coming loose
4: the antenna wire breaking

Feel free to edit this, but something along the lines of what model rockets use to deploy parachutes. Except you don't have to destroy the miniboy, just make it easy for the tail to detach on impact or something, that way the antenna stays above ground.

If I went with the route I'd drop the transmitter all together and just have MiniBoy eject some sort of streamer to sit on the surface. The problem with this is the timing of any 'motor' or ejecting (such as pressure via dry ice) method. Model rockets deploy the 'chute when the motor stops. I don't really want a motor to be ignited inside the MiniBoy during flight.

Your post has given me a few things to think about during my Geology (*sigh*) lecture now so, thanks

Godf*ckingdammit, my epoxy and resin is long expired, had only noticed it recently in the garage but my brother says he got it 2 years or so ago.

That's another $40 (assuming 1 litre is even enough for 200g/kg, 2m^2) on top of the $22 on the fibreglass cloth itself. Perhaps I should start looking for a replacement barrel.

Edit: Seems as if I'll have to try and find a pipe that can either sleeve the ABS barrel or one that is about 60mm O.D. with 5mm wall thickness. They don't seem to make much pipe in diameters between 50mm O.D. and 60mm O.D.

I'll give that a go tomorrow. I did some reading around and everyone basically says it's useless and a shelf life of a year requires suitable temperatures (we don't get extremes where I live which helps, apparently).